Two grand exhibitions on Christian Dior are running concurrently—one at London’s Victoria and Albert Museum and the other at the Dallas Museum of Art. Central to both shows is the black-and-cream suit called Bar, a stunner from the House of Dior’s first collection, La Ligne Corolle (also known as the “New Look”), shown in February of 1947. Many think Bar was the best-selling model of that first collection. It was not. The best-sellers were New York, Maxim’s, 1947, and Amour. Bar, however, was the collection’s signature look, because it spoke volumes.

What did it say? Society women at that time, the curator and archivist Marika Genty explained, could only meet for drinks in “the bar at the best hotels.” Bar was a suit for socializing. Yet its meaning went deeper. Dior had emerged from the heady aesthetic mix that was Paris in the 1930s—painting, architecture, performance; pals Cocteau, Bérard, Dalí, Poulenc, Dufy. As the fabric designer Andrée Brossin de Méré once said, “The first collection was a cocktail of a whole series of artists.” Bar’s fitted jacket recalled the corseted barmaid in Manet’s Bar at the Folies-Bergère, while its huge pleated skirt nodded to the plenitude in royal portraits by Winterhalter, to the native dress of Marseilles fishwives, to the corolla of a rose.

So … a bow to the Belle Époque, a totem of postwar fertility, an echo chamber of artistic allusions, a reflowering. Bar spoke for Dior, his belief in fashion as a blossom of civilization, brilliantly social and endlessly communicative. Catch these shows before they close on September 1. —Laura Jacobs